References:

ITER git repository: https://git.iter.org/projects/IMEX/repos/gittest/browse
ACH gitlab repository: https://gitlab.eufus.psnc.pl/ach/gittest

1. Step by step instructions:

1. Create or select origin repository, in this case it was ITER git repository

2. Clone origin repository with --mirror flag:

   git clone --mirror ssh://git@git.iter.org/imex/gittest.git

3. Change directory to newly cloned mirror repository:

   cd gittest.git

4. Push mirrored repository to new origin with --mirror  flag:

   git push --mirror git@gitlab.eufus.psnc.pl:ach/gittest.git

   Warning!

   Don’t use git push --mirror in repositories that weren’t cloned by --mirror as well. It’ll overwrite the remote repository with your local references (and your local branches).

5. Clone newly pushed repository and change directory to it:

   cd ..git clone git@gitlab.eufus.psnc.pl:ach/gittest.gitcd gittest

6. Check current remote repository:

   git remote -v

   It shall print:

   origin    git@gitlab.eufus.psnc.pl:ach/gittest.git (fetch)
   origin    git@gitlab.eufus.psnc.pl:ach/gittest.git (push)

7. Rename current default remote repository label to more relevant name:

   git remote rename origin gitlab

   And check the result:

   git remote -v

   It shall print:

   gitlab    git@gitlab.eufus.psnc.pl:ach/gittest.git (fetch)
   gitlab    git@gitlab.eufus.psnc.pl:ach/gittest.git (push)

8. Add second remote (ITER, original one):

   git remote add iter ssh://git@git.iter.org/imex/gittest.git

   And check results:

   git remote -v

   It shall print:

   gitlab    git@gitlab.eufus.psnc.pl:ach/gittest.git (fetch)
   gitlab    git@gitlab.eufus.psnc.pl:ach/gittest.git (push)
   iter    ssh://git@git.iter.org/imex/gittest.git (fetch)
   iter    ssh://git@git.iter.org/imex/gittest.git (push)

9. To push or pull to different remote:
   1. PUSH:
      

      1. Gitlab:

         git push gitlab <optionally-branch-name}

      2. ITER:

         git push iter <optionally-branch-name>

         Note

         First push to newly added remote should be executed with {--set-upstream} flag, e.g.:

         git push --set-upstream iter master

   2. PULL:
      

      1. Gitlab:

         git pull gitlab <optionally-branch-name>

      2. ITER:

         git pull iter <optionally-branch-name>